Answer:
C)two thirds x + 10 = 21
Explanation:
The equation for determining how much it would be paid for the student tickets is shown below:
Given that
The ticket of an adult is $21
Now let us assume the price of the student ticket be x
So two third would be 2 ÷ 3x
And for adult it would be
2 ÷ 3x + 10
Now the equation is
2 ÷ 3x + 10 = 21
So after solving this the option c is correct
And the rest of the options are wrong